Fragile articles such as the above-mentioned precious artistic work, left in a cabinet, a whatnot, or a showcase, are prone to tumble or fall down to fracture depending on the tremors when an earthquake occurs. Usually, the articles are guarded by tautened rope or bracing that surrounds the articles. As to a particularly large artwork object, several lines of rope are typically tautened and spread out at a certain distance from each other. However, such methods are unsatisfactory as a full protection means from articles' tumbling or falling down. Such methods give esthetically adverse effects as well as bothering obstacles to viewers.
In order to overcome the aforementioned disadvantages, there has been proposed an anti-vibration protecting plinth that comprises a holder holding an object seated thereon, a sensor for detecting vibrations, a releasing means receiving a signal from the sensor for making the holder release the object, and a protecting means located under the holder to serve as a buffer to receive the object dropped as a result of the releasing by the holder where the releaser includes a solenoid device activated by the signal from the sensor and a stopper disengaged from the holder by means of the solenoid device (see Patent Document 1 listed below).
Another type of plinth has been disclosed that comprises a base of a certain height with a pair of apertures opposed to each other in the top and bottom plates of the base where the aperture in the top plate can be opened and closed by sliding a pair of shutters that meet each other at the center of the aperture while the bottom plate is skirted around the aperture by a shock-absorbing and volume-adjustable bag with its upper open end fixed to a bottom plate so that the bag hangs down and is ready to trap an artistic object fallen from its seated location. This type of plinth further comprise an actuator and a vibration sensor, and the vibration sensor detects vibrations caused by an earthquake and makes the actuator move the shutters to open the aperture, so as to protect the artistic object from damages (see Patent Document 2 listed below).
Patent Document 1: Japanese Patent No. 2746253
Patent Document 2: Japanese Patent No. 3458089
In the anti-vibration protecting plinths as disclosed in Patent Document 1, after the object released from the holder is received at the shock-absorbing bottom of a box-shaped trap, the box-shaped trap has its upper opening closed by means of a trapdoor under the control of the releaser, thereby simply preventing the object from fracturing as a result of its being released through a drop into the trap. In short, the invention disclosed in Patent Document 1 functions to protect the released object in the trap from other droppings.
In practice, however, even if the trap of the plinth is provided with a shock-absorbing element such as sponge as is usually supposed to be, the object such as a chinaware article, when dropped from a height of its originally seated floor down onto the bottom of the trap by the gravitational force, is very likely to fracture. Thus, the invention disclosed in Patent Document 1 may be useful to protect the object from an impact given by other external objects during an earthquake, but substantially not to protect the delicately fragile object such as a chinaware article from the impact caused by a free fall of the object itself within the trap of the plinth.
In the earthquake-proof plinth as disclosed in Patent Document 2, it is noticeable that the bag is elastic and easily and assuredly adjustable in volume, and that the elasticity and adjustability are sufficient to serve as a means to protect the object against damage due to its free fall within the trap of the plinth. An arrangement where “the bottom plate is skirted around the aperture by a shock-absorbing and volume-adjustable bag with its upper open end fixed to the bottom plate so that the bag hangs down and is ready to trap an artistic object fallen . . .” advantageously utilizes a shock-absorbing property derived from an elastic property of the bag, and unless the object has a portion cornered or shaped in an extraordinarily sharpened cone, the bag can transform itself to softly embrace the object of any shape as a result of a small impact by such a dropping. The middle portion of the bag can be squeezed by tightening a strip to adjust a volume of the trap with ease. In addition, if the artistic object such as a chinaware article seated on the plinth is replaced from time to time and even if the replaced object is varied in shape and/or dimensions from before, the volume of the trap in the bag can be easily varied from one object to another as required, which is advantageous to minimize the impact caused by the act of dropping and also to prevent the object in the bag from spinning as a result of the dropping.
In the event of displaying an object, such as an porcelain article with flame-shaped frills around its upper rim and other uniquely contoured vases, that has a relatively large protrusion(s) from a main body, the box-shaped trap in the earthquake-proof plinth as disclosed in Patent Document 1 is very likely to fail to sufficiently absorb the impact upon receiving the dropped object at its shock-absorbing bottom to let the protrusion(s) of the object break off or crush into pieces.
The earthquake-proof plinth as disclosed in Patent Document 2 is capable of providing sufficient impact protection to a dropped object that has no protrusion(s). In the presence of relatively large protrusion(s) from the object, the pair of shutters, opening or closing between the periphery and the center of the opening at the top of the plinth, are prone to bump the protrusion(s) of the object to break it (them) off or crush it (them) into pieces.
The present invention is made to overcome the aforementioned disadvantages recognized in the prior art, and accordingly, it is an object of the present invention to provide an earthquake-proof plinth having a mechanism that can drop an article vertically on a seat while keeping the seat in its original horizontal orientation, and then, stop the article in the course of dropping by means of a shock-absorbing means, so that the article even with a protrusion(s) can be, as a whole, protected from an impact as it is dropped.
It is another object of the present invention to provide an earthquake-proof plinth having a mechanism that holds a middle section of an article to prevent it from tumbling down, so that the article seated on the plinth and its protrusion(s) can avoid damages, and especially, the mechanism can effectively prevent the protrusion(s) from being crushed or breaking off.